/Engine/Source/Runtime/CoreUObject/Public/UObject/PackageResourceManager.h
OpenAsyncReadPackage that takes a PackageSegment
[FOpenAsyncPackageResult](API\Runtime\CoreUObject\UObject\FOpenAsyncPackageResult) OpenAsyncReadPackage ( const [FPackagePath](API\Runtime\CoreUObject\Misc\FPackagePath) & PackagePath, EPackageSegment PackageSegment )